Hormone replacement therapy with L-thyroxine promotes working memory and concentration in thyroidectomized female patients after differentiated thyroid carcinoma.

Objective: It is well established that long-term hypothyroidism is associated with cognitive deficits. Based on recent literature, we hypothesized that pharmacologically induced euthyroidism would lead to improved cognitive performance compared to a hypothyroid state. Methods: We analyzed data from 14 nondepressed thyroidectomized female patients after differentiated thyroid carcinoma during hypothyroidism (due to a four-week withdrawal of thyroid hormone, T1) and euthyroidism brought about by substitution with L-thyroxine (T2). At both measurement points, patients completed a cognitive test battery as our dependent measure and Beck's Depression Inventory to control depressive states. Results: A Wilcoxon signed-rank tests revealed a significant improvement in the Rey­Osterrieth complex figure test (cognitive reproduction), Z = −3.183, p = 0.001, and the D2 concentration score, Z = −1.992, p = 0.046 in euthyroidism compared to hypothyroidism. Conclusions: Our results confirm that hormone replacement therapy with L-thyroxine promotes cognitive reproduction and concentration in thyroidectomized female patients after differentiated thyroid carcinoma.

Effect fingerprints of antipsychotic drugs on neural networks in vitro.

We compared the acute effect of typical (haloperidol) and atypical (aripiprazole, clozapine, olanzapine) antipsychotic drugs (APDs) on spontaneous electrophysiological activity of in vitro neuronal networks cultured on microelectrode arrays (MEAs). Network burst analysis revealed a "regularizing" effect of all APDs at therapeutic concentrations, i.e., an increase of network-wide temporal synchronization. At supratherapeutic concentrations, all APDs but olanzapine mediated a decrease of burst and spike rates, burst duration, number of spikes in bursts, and network synchrony. The rank order of potency of APDs was: haloperidol > aripiprazole > clozapine > olanzapine (no suppression). Disruption of network function was not due to enhanced cell death as assessed by trypan blue staining. APDs promoted distinct concentration-dependent alterations yielding acute effect fingerprints of the tested compounds. These effects were rather characteristic for individual compounds than distinctive for typical vs. atypical APDs. Thus, this dichotomy may be of value in distinguishing clinical features but has no apparent basis on the network or local circuitry level.

Oxytocin reactivity to an emotional challenge paradigm and its relation to social-cognitive functions in healthy volunteers.

The neuropeptide oxytocin (OT) is known to be an important modulator of social cognition. It has been shown that lower OT plasma concentrations are linked to impairments in social cognition. Studies have also shown that intranasal OT may enhance social-cognitive abilities in healthy subjects. We hypothesize that, besides baseline OT concentrations, the reactivity of the OT system may have an important role in social-cognitive functioning of individuals. In the present study, we explored if an emotional challenge paradigm is suitable to elicit OT release into plasma to make the reactivity of the OT system measurable. Therefore, 20 healthy male volunteers watched an emotional film clip, showing another person in pain during a severe dentist's treatment, while blood draws were conducted pre and post challenge. OT concentrations in plasma were measured by ELISA after solid phase extraction from plasma. OT plasma concentrations at baseline were significantly negatively correlated to an empathetic rating of our film clip and to measures of emotional empathy for positive and negative emotions, whereas the difference between post-challenge value and baseline was significantly positively correlated with the latter measures. Our data thus show that a short emotional video can be successfully employed as a challenge paradigm for eliciting an increase of peripheral OT in healthy male subjects. Calculating the relative OT change post- vs. pre-challenge may give a measure of OT reactivity. The combination of low peripheral OT at baseline with high OT reactivity may be a psychoendocrine trait that is linked to higher emotional functioning.

Proteomic, genomic and translational approaches identify CRMP1 for a role in schizophrenia and its underlying traits.

Schizophrenia is a chronic illness of heterogenous biological origin. We hypothesized that, similar to chronic progressive brain conditions, persistent functional disturbances of neurons would result in disturbed proteostasis in the brains of schizophrenia patients, leading to increased abundance of specific misfolded, insoluble proteins. Identification of such proteins would facilitate the elucidation of molecular processes underlying these devastating conditions. We therefore generated antibodies against pooled insoluble proteome of post-mortem brains from schizophrenia patients in order to identify unique, disease-specific epitopes. We successfully identified such an epitope to be present on collapsin-response mediator protein 1 (CRMP1) in biochemically purified, insoluble brain fractions. A genetic association analysis for the CRMP1 gene in a large Finnish population cohort (n = 4651) corroborated the association of physical and social anhedonia with the CRMP1 locus in a DISC1 (Disrupted-in-schizophrenia 1)-dependent manner. Physical and social anhedonia are heritable traits, present as chronic, negative symptoms of schizophrenia and severe major depression, thus constituting serious vulnerability factors for mental disease. Strikingly, lymphoblastoid cell lines derived from schizophrenia patients mirrored aberrant CRMP1 immunoreactivity by showing an increase of CRMP1 expression, suggesting its potential role as a blood-based diagnostic marker. CRMP1 is a novel candidate protein for schizophrenia traits at the intersection of the reelin and DISC1 pathways that directly and functionally interacts with DISC1. We demonstrate the impact of an interdisciplinary approach where the identification of a disease-associated epitope in post-mortem brains, powered by a genetic association study, is rapidly translated into a potential blood-based diagnostic marker.

Multielectrode array analysis of cerebrospinal fluid in Alzheimer's disease versus mild cognitive impairment: a potential diagnostic and treatment biomarker.

Pathological cerebrospinal fluid (CSF) alterations like changes in amyloid-ß1-42 and tau protein concentration are typical in Alzheimer's disease (AD). However, it remains unclear, if the composition of known or unknown pathological factors in native CSF has a functional significance in AD. In this pilot study, we used multielectrode array (MEA) neurochips to determine whether CSF of individuals with AD (AD-CSF) may have distinct neurofunctional properties that may distinguish it from that of individuals with mild cognitive impairment (MCI) - a differential diagnosis of high clinical importance. MEAs are neuronal cultures coupled to a multisite electrical recording system with the ability to reflect pharmacological or toxicological alterations on the functional level of whole neuronal networks. Collective rhythmical electrical activity was substantially enhanced after exposure to CSF of cognitively healthy subjects (controls) and of MCI individuals (MCI-CSF) alike. However, this activity increment was significantly reduced when MEAs were exposed to AD-CSF compared to MCI-CSF. Moreover, following AD-CSF exposure, networks showed significantly enhanced burst durations and less synchronous bursting, respectively. Thus, AD-CSF and MCI-CSF could be distinguished by characteristic changes of the network firing pattern on MEAs. When data of MCI individuals and AD patients were pooled, the network suppression correlated significantly with the degree of cognitive decline. The findings of this pilot study may set the stage for a unique and straightforward diagnostic bioassay of AD with particular value in the differential diagnosis to MCI and as a much needed biomarker for clinical trials.

Nicotinic acetylcholine receptor expression on B-lymphoblasts of healthy versus schizophrenic subjects stratified for smoking: [3H]-nicotine binding is decreased in schizophrenia and correlates with negative symptoms.

Heavy smoking and schizophrenia are diversely associated with nicotinic acetylcholine receptor expression, as was shown for brain and lymphocytes. Most studies so far have not systematically differentiated between schizophrenia smokers and non-smokers and were confined either to in vivo or post-mortem study approaches. In order to avoid variable in vivo influences or post-mortem bias, we used stably transformed B-lymphoblast cultures derived from healthy and schizophrenia subjects stratified for smoking versus non-smoking in order to differentiate these clinical conditions with regard to nicotinic acetylcholine receptor expression and regulation. Receptor quantities were measured using [(3)H]-nicotine and [(3)H]-epibatidine binding. At baseline, [(3)H]-nicotine binding was not statistically different between healthy smokers and never-smokers (1.59 ± 0.73 vs. 1.26 ± 0.91 fmol/10(6) cells), while it was reduced in schizophrenia smokers compared to healthy smokers (1.05 ± 0.69 fmol vs. 1.44 ± 0.84/10(6) cells, P = 0.01). In schizophrenia, baseline [(3)H]-nicotine correlated inversely with higher PANSS negative subscale scores. After long-term nicotine incubation (1 µM), [3H]-nicotine binding increased in the group of schizophrenia smokers only (from 1.05 ± 0.69 to 1.54 ± 0.77 fmol/106 cells, P = 0.013), while [(3)H]-epibatidine binding decreased in this group (4.52 ± 1.52 to 3.82 ± 1.38 fmol/10(6) cells, P = 0.038). Our data are in further support of a decrease of nicotinic acetylcholine receptor expression in schizophrenia linked to negative psychotic symptoms, which may be counter-regulated by nicotine exposure.

Clomipramine-induced serum prolactin as a marker for serotonin and dopamine turnover: results of an open label study.

Central nervous system (CNS) monoamine deficits have been linked to a number of pathological conditions such as major depressive disorder. Individual biological variations in 5-hydroxyindoleacetic acid (5-HIAA), homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) might account for the variation in responses of neurotransmitter systems observed after the administration of clomipramine. The prolactin response to clomipramine has been widely used to assess CNS functioning. This open label study investigates the prolactin response induced by clomipramine in the plasma of healthy volunteers and whether it is related to changes in monoamine metabolites. The effects of clomipramine challenge on prolactin, 5-HIAA, HVA and MHPG were measured in 12 healthy volunteers. Samples were drawn directly before and 50 min after clomipramine infusion. A statistically significant increase in serum prolactin concentrations was measured in women 50 min after CMI infusion, but not in men. We found no significant increases in the serum monoamine metabolite concentrations 50 min after CMI infusion. Changes in HVA and 5-HIAA correlated statistically significantly and positively with the amount of prolactin release in the whole sample. Furthermore, positive correlations were found between ∆(50-0 min) 5-HIAA and ∆(50-0 min) HVA, although we did not find a correlation between ∆(50-0 min) prolactin and ∆(50-0 min) MHPG after clomipramine challenge. The pronounced prolactin release in healthy adult women might indicate a higher physiological sensitivity. Correlations between intra-individual changes in HVA, 5-HIAA and serum prolactin might indicate a central nervous effect of clomipramine on monoamine turnover. We conclude that monoamine changes in relation to prolactin response after clomipramine challenge may be suitable for characterizing the relationship between central serotonergic and dopaminergic function.

Abnormal neuroendocrine response to clomipramine in hereditary affective psychosis.

BACKGROUND: Blunting of prolactin response after serotonergic stimulation during a major depressive episode has been described by several investigators. In this study, the neuroendocrine responses to clomipramine were assessed in remitted patients suffering from hereditary depression. METHODS: Twenty remitted patients from 11 large families with multigenerational, multiple cases of major affective disorder (bipolar disorder n=15, recurrent depression n=5, according DSM-IV) and 12 healthy relatives were investigated. After intravenous application of 12.5 mg of the serotonin re-uptake inhibitor clomipramine, serum prolactin and cortisol levels were analysed. RESULTS: Patients and comparison group did not differ significantly with respect to age, baseline prolactin and cortisol concentrations. A gender effect was found in an exploratory analysis for prolactin but not for cortisol and therefore the data for prolactin were analysed separately. After clomipramine infusion, the increase of cortisol was significantly lower in patients than in the comparison group (P=.046). For prolactin, this effect could be found in the male (P=.012) as well as in the female (P=.007) subsample. CONCLUSIONS: These results suggest that blunted prolactin and cortisol responses to serotonergic stimulation are characteristic for remitted depressive patients with previous episodes of major affective disorders.

Antidopaminergic medication in healthy subjects provokes subjective and objective mental impairments tightly correlated with perturbation of biogenic monoamine metabolism and prolactin secretion.

OBJECTIVES: Off-label prescription of antipsychotics to patients without psychotic symptoms has become a routine matter for many psychiatrists and also some general practitioners. Nonetheless, little is known about the possibly detrimental effects of antidopaminergic medications on general psychopathology, subjective mental state, or a possible association with physiological parameters in nonpsychotic individuals. METHODS: In this randomized, single-blinded study, groups of healthy volunteers (n=18) received low doses of reserpine, aripiprazole, haloperidol, or placebo on 7 successive days. Relevant physiological parameters (plasma prolactin, concentrations of catecholamine metabolites in plasma, and 24-hour urine) and each subject's mental state (Positive and Negative Syndrome Scale, Hamilton Rating Scale for Depression, visual analogue scale, Beck Depression Inventory II) were assessed at the start and end of the trial. RESULTS: Of the three active treatments, only reserpine caused a significant increase in some plasma- and urine-catecholamine metabolites, but all three medications evoked objective and subjective changes in general psychopathology scores, which correlated with individual increases in plasma homovanillic acid concentrations. Both objective and subjective impairments were significantly more pronounced in the subgroup with greatest increase of plasma prolactin. Subjects experiencing the most pronounced side effects under haloperidol, which compelled them to drop out, showed significantly higher prolactin concentration increases than those who tolerated haloperidol well. CONCLUSION: We found consistent associations between altered markers of dopamine transmission and several objective and subjective mental impairments in healthy volunteers after 1 week's treatment with antidopaminergic medications. These findings should draw attention to a more intensive risk-benefit evaluation in cases of off-label prescription of antipsychotic medications.

Effects of varenicline on alpha4-containing nicotinic acetylcholine receptor expression and cognitive performance in mice.

Nicotinic acetylcholine receptor (nAChR) subtypes containing the α4 subunit, particularly α4ß2 nAChRs, play an important role in cognitive functioning. The impact of the smoking cessation aid varenicline, a selective partial α4ß2 nAChR agonist, on (1) changes of central protein and mRNA expression of this receptor and (2) on memory deficits in a mouse model of cognitive impairment was investigated. Protein and mRNA expression of both the α4 and ß2 receptor subunits in mouse brain endothelial and hippocampal cells as well as hippocampus and neocortex tissues were determined by western blot and realtime PCR, respectively. The ß2 antibody showed low specificity, though. Tissues were examined following a 2-week oral treatment with various doses of varenicline (0.01, 0.1, 1, 3 mg/kg/day) or vehicle. In addition, episodic memory of mice was assessed following this treatment with an object recognition task using (1) normal mice and (2) animals with anticholinergic-induced memory impairment (i.p. injection of 0.5 mg/kg scopolamine). Varenicline dose-dependently increased protein expression of both the α4 and ß2 subunit in cell cultures and brain tissues, respectively, but had no effect on mRNA expression of both subunits. Scopolamine injection induced a significant reduction of object memory in vehicle-treated mice. By contrast, cognitive performance was not altered by scopolamine in varenicline-treated mice. In conclusion, a 2-week oral treatment with varenicline prevented memory impairment in the scopolamine mouse model. In parallel, protein, but not mRNA expression was upregulated, suggesting a posttranscriptional mechanism. Our findings suggest a beneficial effect of varenicline on cognitive dysfunction.

Increased levels of glucocorticoid receptors and enhanced glucocorticoid receptor auto-regulation after hydrocortisone challenge in B-lymphoblastoids from patients with affective disorders.

The stress response is mediated by a negative feedback effect of glucocorticoids on corticosteroid receptors. Here, we examine the potential contribution of these receptors and their response to a glucocorticoid challenge to dysfunctions of the hypothalamic-pituitary-adrenal axis reported for patients with affective disorders. In a pilot-study, we established B-lymphoblastoid cell lines from patients suffering from affective disorders and healthy subjects and measured the quantity of glucocorticoid receptors at steady state conditions after 12-weeks cell culture. After short-term incubation with 0.1 microM hydrocortisone for 48 h, the decrease of glucocorticoid receptors was also investigated. After 12-weeks cell culture, we found a significantly higher number of cytosolic glucocorticoid receptors in B-lymphoblastoids from patients (B(max)=804.9+/-342.5 fmol/mg protein) compared to those from healthy subjects (B(max)=576.9+/-190.3 fmol/mg protein: p=0.045; t-test). The increase of the glucocorticoid receptor level in the group of patients could be attributed largely to the higher number of these receptors measured in B-lymphoblastoids of patients suffering from major depressive disorder. The in vitro regulation of glucocorticoid receptors in response to 0.1 microM hydrocortisone for 48 h resulted in a significantly larger decrease in cultures of B-lymphoblastoids derived from patients (to 32.9+/-7.5%) than in those from healthy subjects (to 45.8+/-8.2%). The stronger decrease of glucocorticoid receptors in the group of patients (p=0.0001; t-test) was independent of the duration of illness and medication, suggesting a trait-like characteristic of the response.

Increased serum S100B in elderly, chronic schizophrenic patients: negative correlation with deficit symptoms.

In schizophrenia, elevations of serum and CSF S100B levels have been reported and related to state of the disease and negative symptoms. In elderly chronic schizophrenic inpatients with stable medication, S100B may be increased and correlated to psychopathology and neuropsychological deficits. We have measured serum levels of S100B in 41 elderly, chronic schizophrenic patients and 23 age- and gender-matched controls using an immunoluminometric assay. In patients, we assessed detailed psychopathology and neuropsychological performance and determined serum levels of haloperidol, clozapine and its two main metabolites desmethylclozapine and clozapine metabolite N-oxid by HPLC. S100B levels were increased in elderly chronic schizophrenic patients compared to healthy controls. In patients, levels were negatively correlated with deficit symptoms and positively with age. There were no significant differences of S100B between medication groups and no correlation with serum levels of antipsychotics or neuropsychological scores. Elevations of S100B in elderly chronic schizophrenic patients may be related to an active disease process lasting until old-age. Correlations point to the impact of S100B in neuroplasticity and ageing. Post-mortem studies should clarify the presence of altered S100B function in the brain and its relationship to neuroplastic or neurodegenerative processes.

Neuropsychological measures of attention and memory function in schizophrenia: relationships with symptom dimensions and serum monoamine activity.

BACKGROUND: Some clinical symptoms or cognitive functions have been related to the overall state of monoamine activity in patients with schizophrenia, (e.g. inverse correlation of the dopamine metabolite HVA with delusions or visual-masking performance). However, profiles (as presented here) of the relations of the activity of dopamine, noradrenaline and serotonin to neuropsychologic (dys)functions in major patient sub-groups with their very different symptomatic and cognitive characteristics have not been reported. METHODS: Serum measures of dopamine, noradrenaline and serotonin turnover were examined by regression analyses for the prediction of performance on 10 neuropsychological measures reflecting left- and right-hemispheric and frontal-, parietal- and temporal-lobe function in 108 patients with schizophrenia and 63 matched controls. The neuropsychological battery included tests of verbal fluency, Stroop interference, trail-making, block-design, Mooney faces recognition, picture-completion, immediate and delayed visual and verbal recall. Paranoid and nonparanoid subgroups were based on ratings from the Positive and Negative Syndrome Scale (PANSS). Groups with high and low ratings of ideas-of-reference and thought-disorder were formed from a median split on the Scale for Assessment of Positive Symptoms (SAPS). RESULTS: Verbal-fluency and Stroop-interference (left frontal and fronto-cingulate function) were negatively associated with noradrenergic turnover in nonparanoid and thought-disordered patients. High dopamine turnover related to speeded trail-making (frontal modulation of set switching) in those with many ideas-of-reference. In contrast, low dopamine turnover predicted poor recall in nonparanoid patients and those with little thought disorder. Serotonin metabolism did not independently contribute to the prediction any measure of cognitive performance. But, with regard to the relative activity between monoaminergic systems, increased HVA/5-HIAA ratios predicted visual-reproduction and Mooney's face-recognition performance (right-hemisphere functions) in highly symptomatic patients. Decreased HVA/MHPG predicted non-verbal recall. CONCLUSION: Clinical state and function are differentially sensitive to overall levels of monoamine activity. In particular, right-lateralised cerebral function was sensitive to the relative activities of the monoamines. Increased noradrenergic activity was associated with enhanced frontal but impaired temporal lobe function in nonparanoid syndromes. Low dopaminergic activity predicted poor attentional set control in those with ideas-of-reference, but poor recall in nonparanoid patients. These data, especially the HVA/5-HIAA ratios, provide a basis for planning the nature of antipsychotic treatment aimed at patient specific symptom dimensions and cognitive abilities.

Influence of synaptic serotonin level on [18F]altanserin binding to 5HT2 receptors in man.

The feasibility of in vivo serotonin 5HT(2) receptor binding measurement using [18F]altanserin as a radioligand has been well established. In this study, the postsynaptic receptor binding potential of this ligand was examined as a possible indicator of synaptic serotonin content after pharmacological challenge. Studies were performed in 11 subjects with a history of recurrent major depression. Six of them received serotonergic antidepressive treatment at the time of the experiment, the other five patients were untreated. Two PET measurements were carried out in each subject within 2 or 3 days. Before one of the measurements, 25 mg of the serotonin re-uptake inhibitor clomipramine were given intravenously, the other measurement was done without pharmacological challenge. The data were analyzed using non-linear least-square regression and Logan's graphical method. In the whole group of subjects, binding potential and distribution volume of altanserin decreased following clomipramine challenge. The decrease was between 14 (P=0.03) and 23% (P=0.004). This effect was mainly seen in subjects not on antidepressive medication. Clomipramine challenge probably increased the synaptic serotonin level, which competed with altanserin leading to the lowered binding potential. The paradigm might, thus, be useful to estimate serotonin release in vivo. Pretreatment with serotonergic antidepressants reduces the effect of clomipramine.

Antipsychotic drugs influence transport of the beta-adrenergic antagonist [3H]-dihydroalprenolol into neuronal and blood cells.

The amine hypothesis suggests that the cause of schizophrenic or depressive psychosis is dysfunction of noradrenergic or serotonergic neurotransmission. We investigated pharmacological properties of [3H]-dihydroalprenolol (DHA) transport into C6, IMR32, native lymphocytes, B-lymphoblastoids and MOLT-3 cells. DHA transport was inhibited by a heterogeneous group of structurally related compounds exhibiting an amine group and various aromatic ring structures. It was verified on cells of neuronal/glial and blood cell origin but in detail on B-lymphoblastoids. The latter once showed strongest inhibition of DHA transport using tricyclic antidepressants (amitriptyline: IC50 = 2.86 microM, imipramine: IC50 = 3.33 microM) and haloperidol (IC50 = 3.98 microM) as a neuroleptic. Antipsychotics like clozapine (IC50 = 11 microM), olanzapine (IC50 = 15 microM), spiperone (IC50 = 66 microM) and EMD 49980 (ICso >> 100 microM) were less effective. In contrast to cells of blood origin, a stimulation of DHA transport by antipsychotics was not detectable using neuronal cells. As antipsychotics showed a distinct inhibition and, concerning cells of blood origin, a stimulation of transport after pre-incubation, further investigations seem to be of interest in respect to its involvement in the cellular uptake of drugs and therefore its impact on the quality of therapy of psychiatric patients.

Peripheral DISC1 protein levels as a trait marker for schizophrenia and modulating effects of nicotine.

The Disrupted-in-Schizophrenia 1 (DISC1) protein plays a key role in behavioral control and vulnerability for mental illnesses, including schizophrenia. In this study we asked whether peripheral DISC1 protein levels in lymphocytes of patients diagnosed with schizophrenia can serve as a trait marker for the disease. Since a prominent comorbidity of schizophrenia patients is nicotine abuse or addiction, we also examined modulation of lymphocyte DISC1 protein levels in smokers, as well as the relationship between nicotine and DISC1 solubility status. We show decreased DISC1 levels in patients diagnosed with schizophrenia independent of smoking, indicating its potential use as a trait marker of this disease. In addition, lymphocytic DISC1 protein levels were decreased in smoking, mentally healthy individuals but not to the degree of overriding the trait level. Since DISC1 protein has been reported to exist in different solubility states in the brain, we also investigated DISC1 protein solubility in brains of rats treated with nicotine. Sub-chronic treatment with progressively increasing doses of nicotine from 0.25mg/kg to 1mg/kg for 15 days led to a decrease of insoluble DISC1 in the medial prefrontal cortex. Our results demonstrate that DISC1 protein levels in human lymphocytes are correlated with the diagnosis of schizophrenia independent of smoking and thus present a potential biomarker. Reduced DISC1 protein levels in lymphocytes of healthy individuals exposed to nicotine suggest that peripheral DISC1 could have potential for monitoring the effects of psychoactive substances.

The impact of antipsychotic drugs on food intake and body weight and on leptin levels in blood and hypothalamic ob-r leptin receptor expression in wistar rats.

OBJECTIVES: The aim of our study was to investigate the impact of typical and atypical antipsychotic drugs on leptin concentration in blood and changes in the receptor expression in the hypothalamus of male Wistar rats. METHODS: From the age of 13 to 18 weeks, three groups of 20 animals were fed an average dose of 3.5 + 0.03 mg/ kg body weight (BW) haloperidol; 30.6 + 0.22 mg/kg BW clozapine; or 14.9 + 0.13 mg/kg BW ziprasidone in ground food pellets containing 15% fat. Twenty control animals received no drugs. Blood samples were taken at week 14, 16, and 19. Locomotor activity and exploratory behavior were measured using the alcove test at weeks 15 and 17. The expression of the hypothalamic leptin receptor in rat brains was determined by using a Western blot. RESULTS: Rats medicated with haloperidol and ziprasidone showed a significantly decreased percentage weight gain and food consumption. We observed no differences in the alcove test, but locomotor activity was significantly reduced in the haloperidol group. Except for rats in the clozapine and ziprasidone groups, after 2 weeks of drug application, we found no changes in the leptin blood concentrations among the four groups or animals within each group. Moreover, we did not find specific differences in hypothalamic leptin receptor expression among the groups. CONCLUSION: We concluded that in male Wistar rats during this treatment period, the tested drugs did not act directly on the leptin regulatory system. We recommend further studies using long-term treatment of different rat strains.

Increased serum interleukin-1beta and interleukin-6 in elderly, chronic schizophrenic patients on stable antipsychotic medication.

In schizophrenia, alterations of proinflammatory cytokine levels have been reported and related to the disease and psychopathology. However, only limited conclusions can be drawn in view of confounding factors such as infection, age, sex, smoking, and antipsychotic medication. Chronic schizophrenic patients with a long-term disease process and medication period have not been investigated so far. We have measured serum levels of interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)alpha in 41 elderly, chronic schizophrenic patients and 23 age- and sex-matched controls using enzyme-linked immunosorbent assay (ELISA). We assessed detailed psychopathology and neuropsychological performance and determined serum levels of haloperidol, clozapine, and the two main clozapine metabolites, desmethylclozapine and clozapine metabolite N-oxide, by high-pressure liquid chromatography (HPLC). IL-1beta and IL-6 levels were increased in treatment-resistant schizophrenic patients compared with healthy controls, whereas TNFalpha showed no difference. We did not find statistically significant differences of cytokine levels between medication groups and there was no correlation with serum levels of antipsychotics or psychopathological rating scores. Elevations of IL-1beta and IL-6 in elderly chronic schizophrenic patients may be related to an active disease process lasting until old age. Despite missing correlations, long-term treatment effects in treatment-resistant patients may have affected TNFalpha, leading to control levels. Post-mortem and animal studies should clarify the presence of altered immune function in the brain as well as the effect of cytokine levels in relation to neurodevelopmental disturbances and schizophrenia-associated behavior.

Clozapine induces oxidative stress and proapoptotic gene expression in neutrophils of schizophrenic patients.

The present study examined cellular effects of the atypical antipsychotic drug clozapine on blood cells of treated patients with and without clozapine-induced agranulocytosis (CA). Blood from one patient who commenced clozapine treatment was examined at weekly intervals for 128 days. Olanzapine-treated (n = 5) and polymedicated (n = 14) schizophrenic patients, as well as healthy subjects (n = 19) and septic shock patients (n = 8), were studied for comparison. We observed dramatically increased numbers of native neutrophils stained for superoxide anion production (P < or = 0.005, n = 10) and significantly elevated expression levels of the proapoptotic genes p53 (P < or = 0.020), bax alpha (P < or = 0.001), and bik (P < or = 0.002) in all tested non-CA patients (n = 19) and CA patients (n = 4). In non-CA patients, the expression of these genes did not correlate to the percentage of apoptotic neutrophils (2.0% +/- 1.3%), but in CA patients about 37% of the neutrophils show morphologic signs of apoptosis (P < or = 0.001). Under G-CSF therapy of CA, the number of apoptotic neutrophils and the expression of the proapoptotic genes decreased significantly. In conclusion, high production of reactive oxygen species in neutrophils of clozapine-treated patients, together with increased expression of proapoptotic genes, suggests that neutrophils are predisposed to apoptosis in schizophrenic patients under clozapine therapy. The correlation between drug and proapoptotic markers was highest for clozapine and bax alpha as well as superoxide anion radicals. This indicates oxidative mitochondrial stress in neutrophils of clozapine-treated patients which probably contributes to the induction of apoptosis and sudden loss of neutrophils and their precursors in CA patients.